addressPrefix: string? is no longer needed

Author: DocGailZhou

infra/modules/network/virtualNetwork.bicep

@@ -118,9 +118,6 @@ type subnetType = {
   @description('Required. The Name of the subnet resource.')
   name: string
 
-  // @description('Conditional. The address prefix for the subnet. Required if `addressPrefixes` is empty.')
-  // addressPrefix: string?
-
   @description('Required. Prefixes for the subnet.')  // Required to ensure at least one prefix is provided
   addressPrefixes: string[]